U.S. Secretary of Education Arne Duncan says that some of the opposition to the controversial Common Core state education standards is coming from wealthy "white" mothers upset to learn their children are not as bright as they thought.

Opposition has been building to President Barack Obama's new federal school standards for several months.

But Duncan dismisses the reaction against the standards, calling opponents disgruntled parents who blame the new standards for lowering their children's grades.

"All of a sudden, their child isn't as brilliant as they thought they were and their school isn't quite as good as they thought . . . and that's pretty scary," Duncan said at an event Friday, Politico reported.

After his comments sparked outrage on social media, Duncan told Politico that he "didn't say it perfectly," but that to oppose Common Core is to oppose progress.

The Common Core proficiency standards for English and math have been adopted by 45 states since 2010, according to The Washington Times, but now teachers and parents say the program is poorly designed and costs too much money.

The new educational system was funded with $4 billion through Obama's stimulus package, but Alaska, Nebraska, Texas, and Virginia blocked it and lost out on the money.

Florida notified federal authorities last month that it was pulling out of the program, Minnesota has rejected some of the key standards, and Indiana still has not made a decision.

Opponents nationwide declared Monday "National Don't Send Your Child to School Day," and were planning protests in local school districts. A Facebook page boasted that 6,000 followers would attend the protests.

Opposition also is growing in New York, where Education Commissioner John King held public meetings last week to address parental concerns.

"We are abusing the children in the state of New York," Beth Dimino, president of the Port Jefferson Station Parent Teacher Association, said at a forum, according to Patch.